Changes In Equity (Schedule Of Stockholders Equity) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at the beginning of the period	$ 1,442,928	$ 1,795,179	$ 1,430,525	$ 1,787,889
Net income (loss)	30,859	(315,439)	56,997	(310,717)
Other comprehensive income (loss)	3,385	1,827	337	3,178
Share-based compensation	4,185	5,312	7,692	10,095
Issuance of common stock, net	194	99	(500)	(2,265)
Contributions from noncontrolling interests		2,581		5,379
Distributions to noncontrolling interests	(17,410)		(30,910)	(4,000)
Balance at the end of the period	1,464,141	1,489,559	1,464,141	1,489,559
Common Stock [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at the beginning of the period	50,577	50,180	50,279	50,026
Issuance of common stock, net	194	99	492	253
Balance at the end of the period	50,771	50,279	50,771	50,279
Additional Paid-In Capital [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at the beginning of the period	1,120,487	1,105,184	1,117,972	1,102,919
Share-based compensation	4,185	5,312	7,692	10,095
Issuance of common stock, net			(992)	(2,518)
Balance at the end of the period	1,124,672	1,110,496	1,124,672	1,110,496
Retained Earnings [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at the beginning of the period	331,362	701,325	313,991	701,681
Net income (loss)	18,709	(320,530)	36,080	(320,886)
Balance at the end of the period	350,071	380,795	350,071	380,795
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at the beginning of the period	(43,128)	(44,200)	(42,100)	(45,449)
Other comprehensive income (loss)	2,531	1,670	1,503	2,919
Balance at the end of the period	(40,597)	(42,530)	(40,597)	(42,530)
Noncontrolling Interests [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at the beginning of the period	(16,370)	(17,310)	(9,617)	(21,288)
Net income (loss)	12,150	5,091	20,917	10,169
Other comprehensive income (loss)	854	157	(1,166)	259
Contributions from noncontrolling interests		2,581		5,379
Distributions to noncontrolling interests	(17,410)		(30,910)	(4,000)
Balance at the end of the period	$ (20,776)	$ (9,481)	$ (20,776)	$ (9,481)